Impact of Antarctic Circumpolar Current Development on Late Paleogene Ocean Structure Miriam E. Katz et al. Group. 1 200314234 허록 200914505 공종현 200914535 이승태 201014536 이다솜 /

Modern Antarctic Ocean Clockwise AABW NADW(CDW) Strongest AAIW

Modern Ocean Structure Surface Water Intermediate Water Deep Water Bottom Water Miocene? vs Oligocene?

Pre-mid-Eocene Warmer Climate Closed Passage No ACC /

Tectonic Movement Late Eocene Tasman Gateway Drake Passage Depth(m) NCW SCW S N

Shallow ACC Shallow ACC Antarctic Isolation Ice Sheets Oi-1 ODP Site : Ocean Drilling Project Site ASP5 : Atlantic Slope Project

Shallow ACC δ 18 O Offsets GSR Shallow ACC AAIW Depth(m) SCW NCW S N

Deep ACC 31~30Ma Site 522, 747, 748 δ 18 C Offsets AAIW Deep ACC AAIW Depth(m) NCW SCW S N

Conclusion ACC through the Drake passage followed by rapid deeping of the Tasman gateway from the late Eocene to early Oligocene and more-gradual deeping of the Drake passage through the remainder of the Oligocene. Shallow ACC led to Antarctic Isolation and: allowing large scale ice sheets. Deep ACC strengthened AAIW, NADW and AABW. The modern four-layer ocean structure developed during the early Oligocene as a consequence of the ACC Doubthouse climate Late Paleogene Early Paleogene

Reference Impact of Antarctic Circumpolar Current Developmen on Late Paleogene Ocean Structure Fig.1 to 3/ Miriam E. Katz et al. Antarctic Oceanography / Lecture 5 Thank you.